The U.S. surgeon general says officials are “in desperate need of clarity” on electronic cigarettes to help guide public health policies.

Dr. Vivek Murthy, the country’s senior public health official, addressed the battery-powered devices that heat liquid nicotine during a stop Tuesday in Richmond.

The newly-appointed Murthy says the technology should be embraced if evidence shows e-cigarettes are able to help those who otherwise have trouble quitting smoking.

But he says he’s concerned about them because there are many unanswered questions about health impacts of e-cigarettes.

Murthy also expressed worries over how quickly the use of the products has grown, particularly among youth.

The U.S. Senate confirmed the 37-year-old physician and Harvard Medical School instructor’s nomination in December.

The surgeon general’s office has previously been instrumental in guiding tobacco control.

(AP)